An Improved Image Enhancement Approach based on Retinex Theory

Using the reflectance component of images directly as the output of Retinex enhancement lacks adjustability and removing illuminance completely from the non-uniform image leads to the lack of coordination between gray scales and the visual effects is unsatisfactory. In this paper we propose an improved Retinex grayscales transformation enhancement approach. First, we decompose the image to be enhanced into reflectance component and illuminance component. Secondly, the reflectance component of the image is three-linearly transformed according to actual needs. Thirdly, the non-uniform illuminance component of the image is filtered. Finally, we combine the transformed reflectance component and the corrected illuminance component to be the output of the enhancement. The experiment result shows that the proposed enhancement approach has high-performance.